Locks or latches for doors



Aug. 27, 1957 F. J. BUTTER 2,804,323

LOCKS OR LATCHES FOR DOORS Filed Sept. 24, 1956 FIG .I-

I 33 II 36 FIG .2.

United States Patent 07 LOCKS R LATCHES FOR DOORS Francis J. Butter, Finchfield, Wolverhampton, England, Essrgno; to Josiah Parkes & Sons Limited, Willenhall,

ng an Application September 24, 1956, Serial No. 611,655 Claims priority, application Great Britain April 25, 1956 1 Claim. or. 292-169) I This invention relates to locks and latches for doors and of the cylindrical type, that is to say of the type in which the spring bolt of a separate tubular latch, fitted in a hole which is bored into the door from and at right angles to its shutting edge and runs radially into another and usually larger hole bored through the thickness of the door, is operable by a spring-loaded retractor which can be actuated by either of two rollbacks associated with knobs on opposite sides of the door, the retractor and the rollbacks being accommodated in a casing, usually cylindrical or nearly so, which is fitted in said other or larger hole and usually has axial tubular end extensions affording or fitted with bearings in which said rollbacks, or tubular spindles attached to the rollbacks, are mounted for rotation by knobs.

The particular kind of cylindrical type lock or latch wlth which the invention is concerned is that which is intended for the doors of private rooms, for example bedrooms or bathrooms, and though it has no key-operated locking mechanism, has in the inside knob a push button which, when pushed, prevents the outside knob from turnng. The outside knob can be released for use by turnmg the inside knob and also by pushing-in the latch bolt, the latter provision being made so as to prevent a lock-out in the event of a person, after pushing the button, leaving the room and either pulling the door closed behind him or leaving it open and it being closed by a gust of wind or by someone pulling the outside knob.

In some cylindrical type locks or latches of the kind referred to, the latch bolt is so coupled to the retractor that when the bolt is forced in, as by riding over the usual striking plate as the door is slammed, said bolt has to take with it the retractor and overcome the combined load of the bolt and retractor springs which restore these parts to their normal positions. This coupling of the bolt and retractor not only makes harder the closing of the door by slamming, but every time the door is closed in this way, and irrespective of whether the outside knob is locked against turning or not, more work is put upon the bolt, and particularly its lath or tail, than it should have to do.

According to the present invention, a cylindrical type lock or latch of the kind referred to is characterised in that whereas normal operation of the retractor by either knob-actuated rollback directly withdraws the bolt against the combined load of bolt and retractor springs, direct forcing-in of the bolt, as by riding over the usual striking plate when slamming the door, does not impose the springloading of the retractor upon said bolt. Thus the arrangement is such that the latch bolt never pushes the retractor but moves in freely against its own spring-loading so that slamming is comparatively easy and the retractor is not disturbed.

According to a further feature of the invention, the permitted inward movement of the latch bolt independently of the retractor, when the door is slammed or the latch bolt otherwise directly pressed, is 'utilised, in the event Patented Aug. 27, 1957 of the outside knob having been locked against turning by pressing the button in the inside knob,'to operate a spring-loaded catch so as to release the knob-locking mechanism and thereby free the outside knob for turning. The spring-loaded catch would be carried by the retractor so that the knob-locking mechanism would also be released by turning the inside knob and thereby operating the retractor to draw-in the latch bolt.

The invention will now be more fully described with reference to the embodiment shown in the accompanying drawings; in which:

Figs. 1, 2 and 3 are a sectional front elevation, a sectional plan and a sectional end elevation respectively of a cylindrical type lock or latch of the kind in which the outside knob can be prevented from turning by pushing-in a push, button in the inside knob, and said outside knob can be released for use by either turningthe inside knob or pushing-in the latch bolt.

Referring to the drawings, 10 is the forwardly spring loaded retractor which can be actuated by either of two rollbacks 11, 12 associated with the outsideand inside knobs 13, 14 respectively, said retractor 10 and rollbacks 11, 12 being accommodated in a cylindrical casing 15 with co-axial tubular extensions 16, 17 afiiording bearings in which tubular spindles 18, 19 of the rollbacks 11, 12 are mounted for rotation by the knobs 13, 14 respectively.

The retractor 10 is a generally U-shaped body disposed with its limbs horizontally, the forward ends of said limbs being formed with confronting flanges or claws 20 which take over the T-shaped rear end of the lath or tail 21 of the forwardly spring-loaded latch bolt (see Fig. 3), and said retractor has the usual lateral wings 22 with which the rollbacks 11, 12 co-operate in actuating it to withdraw said bolt 21.

A push button 23 in the inside knob 14 is fixed to one end of a slidable spindle 24 which has fixed to its other end a non-circular block 25 which is always prevented from rotation by being engaged in a corresponding noncircular hole in a fixed stop plate 26 near the rollback operable by the outside knob 13. The rollback 11 associated with the outer knob 13 is formed with a noncircular hole or slot into which an extension of the said block 25 engages when the push button 23 is operated to slide said spindle 24 against spring-loading and so lock the outside knob 13 against turning. When so locked, a notch 27 in said spindle 24 is engaged automatically by a spring-loaded catch 28 slidably mounted in the retractor 10, said catch 28 serving to retain the spring-loaded spindle 24 in its knob locking position.

In the event of the inside knob 14 and its associated rollback 12 being turned whilst the catch 28 is operative to retain the outer knob 13 locked, the withdrawal of the retractor 10 and the latch bolt 21 together in the normal manner causes the latch bolt 21 immediately or after a short initial movement to press rearwardly the catch 28 so that the catch 28 disengages the notch 27 in the spindle 24 and allows the spring-loading on the latter to return it and the button 23 into the non-locking position. On the other hand, in the event of the door being slammed with the outside knob 13 in the locked state, inward movement of the latch bolt 21 against its own spring-loading only takes place independently of the retractor 10, and toward the end of this movement relative to the retractor 10 the latch bolt lath or tail 21 engages and presses rearwardly upon the said catch 28 and so disengages it from the spindle 24, thereby enabling the spring-loading of the latter to come into action and free the outside knob 13 for turning.

In order to provide for freeing the outside knob 13 for turning from outside in the event of an emergency (for example if the only person in the room, having pressed the push button to lock the outside knob, becomes Slldw denly'too' ill to'operate'the inside knob), the outside knob 13 has an aperture giving access for an instrument, such for example as a nail, a penknife blade or a screw-driver end, to a slidable cam bar 29 which can be pushed in against spring-loading so :as to force the retaining catch 28 out of the notch 27 in the'spindleand so tfree the outside knob '13 for turningito gain entry to the room *from outside. a

A double-actinghflical coil spring'SO'betWeenthespindle 24 and the 'cam 'bar29 'is provided for'nrgin'g these parts to their inoperative positions determinedby stop pins 31, 32, on the spindle 24 and cam bar "29 respectively and engaging respectively stop plates33,34, one

vent turning thereof upon depression of said spindle, a

"laterally movable 'catch carried by said retractor and ment of said bolt, a depressible cam bar having va camfixedin the casing 15 and the other fixedinthe outer end of the tubularspindle 18 of the knob'13. The'doubleacting spring'iifl is .sleeved upon a rod 35whichis carried by the non-circular-blockfl'S onfthe' spindle?! and ,slidably engages abore in 'anenlarged 'outer'end or block 36' on"the cam -bar 29.

Having fully described my invention, what I claim'arld desireto-secnre by Letters Patent is: In a door latch mechanism of the type havinga bolt, a 'retra'ctor operatively 'connectedto saidbo'lt'ior moving said bolt inwardly only, said connection permitting independent inward movement of said bolt with respect to said *retractor, 'inner and "outer knobs; each connected to a rollback engageablewith sarid retractor, means for "locking theouter kndb from theinside'of saiddoor comprising a depressible non-rotatable spindle having a push button at one endconcentric with said inner knob and an offset extension at the opposite end engageable with a registering holein the rollback of the outer knob to preming surface at its inner end engageable with saidcatch and having an abutment at its outer end e-xtendingrinto said outer knob for engagement by a tool insertible through an aperture in said outer knob-to depress said cam bar towards said catch to cam the same clear of said notch for unlocking said outer knob in, an emergency, and a spring actingmutually on said spindle and on said cam bar to urge each away from its tdepressediposition whereby either or both are automatically returned to their inoperative positions when one 'or the other hasbeen depressed and thereafter said catch hasbeen'rnoved clear of said notch.

References Cited in the file of this patent UNITED SIATES PATENTS 

